Accuracy attachment for firearms



A, M. CRAIG. ACCURACY ATTACHMENT FOR FIREARMS.

APPLICATION FILED J AN. H, 1919.

Patented. Feb. 22, 1921.

1 v I [.{VTOR A Tron/v15 i UNITED STATES PATENT OFFICE.

ALVIN M. CRAIG, OF NEW HAVEN, CONNECTICUT.

ACCURACY ATTACHMENT FOR FIREARMS.

Specification of Letters Patent.

Application filed January 11, 1919. Serial No. 270,623.

means for increasing the accuracy of fireprojectiles.

arms, meaning by the term firearms to embrace all implements of thischaracter from pistols to cannon in which an explosive charge is used toexpel a projectile or It is an established fact that all classesoffirearms have a tendency to lift at the muzzle when fired, and this istrue to an exaggerated extent in some classes of of firearm, and willessentially prevent the rearms as for instance in machine guns, rapidfiring guns, and pistols, althoughit is true to a more or less extent ofall weapons of this character. understood that when firing at pointblank range, it is customary to aim below the target or thing to be hit,and calculate for the lift of the muzzle. Obviously this calculationcannot be accurately made, and the result is more or less a matter ofguess. My

invention is intended to obviate this difficulty, and further to providean extremely simple and reliable device or attachment which can beapplied to any existing type muzzle lift of the firearm when the latteris discharged. I have found by repeated and practical experiments thatif the barrel of the firearm at the muzzle is provided withan extensionon the underside, it will overcome this tendency to lift, and make theweapon fire straight to the point I at which it is aimed, and byregulating this extension as to length and as to the length of itsradius with relation to the bore of the weapon, the amount of depressionof the gun when fired can be accurately determined. Furthermore, myexperiments have shown that this extension can be made to deflect themuzzle slightly either to one side or the other if desired, but theobvious,

and principal use is to have the extension on the under side of thebarrel so that the impact of the gases as they leave the barrel at thetime of discharge will strike the extension and have a tendency todepress the muzzle, thus compensating for the natural This is 'sothorougy tendency to lift at the discharge. In carrying out this idea I findthat it is better tohave the extension made with a longer radius than isrepresented by the wall of the bore of the weapon,-so that there is someimpact of gases as they expand rapidly after Patented Feb. 22, 1921.

leaving the muzzle and strike the extension. I

The extension can be made as apart of the muzzle or it can be separatelyattached thereto, all of which will be clearly under stood from thedescription which follows.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar reference characters indicatecorresponding parts in all the views.

Figure 1 is a side elevation of a rifle provided with my improvedattachment.

Fig. 2 is a longitudinal section of the attachment in its removable formas applied to the barrel of a firearm.

Fig. 3 is an end view thereof.

Fig.4 is a broken perspective showing the extension embodying myimprovement inte ral with the barrel of a weapon, and

ig. 5 is a longitudinal section of a flash diminishing tube formed toembody my invention.

I have shown a simple form of the invention as applied to a rifle, butthe illustration is by way of example and not with the idea of limitingthe invention to the structure shown, as it will be obvious to themechanic that the extension can be provided for in many ways without inthe least affecting the invention.

In one form of the invention I provide a ring or ferrule 10 which screwsto the threaded end 11 of the barrel of the firearm, and a liporextension 12 projects forward from the under side of the rlng so as toreceive the impact of air and gases as they expand on leaving the muzzleof the weapon. It will be noticed by reference'to Figs. 2 and 3 that thelip or extension 12 corresponds in curvature to the curve of the barrel,and that there is a step-down as shown at 13 between the bore of thebarrel and the inner surface of the lip or extension 12, that is to say,that the inner wall of the lip or.

extension 12 represents a longer radius from the center of the bore ofthe barrel than does the wall of said bore, and I have found in practicethat the changing of this radius has considerable effect onthe actionwhenthe weapon is fired.

Where the attachment is screwed or otherwise detachably fastened to thebarrel, it can be turned a little to the right or left, and this willcause a slight movement of the muzzle in a corresponding direction, andthe impact of the expanding gases will obviously be stronger in the samedirection so that if the tendency is for the weapon to rise and alsomove to the right as quently the case, the extension can be made belowthe muzzle and a little .to the left, and thus the aforesaid tendencywill be counteracted.

In Fig. 4 I have shown an extension 12 which in integral with the barrel14 of the weapon, and in this construction the action is precisely asalready stated.

In Fig. 5 I have shown a barrel fitted with a. tube 15 which is screwedthereto and which is sometimes used to diminish the flash of a firearm,which it does by permitting the gases to expand and confining themduring such expansion. If the upper and forward part of this tube is cutaway as at 16 an extension 17 is produced which has the effect abovenoted, although the action is not as good as in the cases where theextension is connected directly to the muzzle of the Weapon. Thestructure shown in Figs. 1 to 4 acts better as a flash condenser thanthe usual tubular flash absorbers.

So far as my invention is concerned, however, it does not materiallymatter how the extension or lip is provided, but it is an establishedfact that the provision of an extension or li-p as stated will have atendency to deflect the muzzle of the weapon to which it is attached asherein stated.

Attention is called to the fact that there is no chance for the gases toescape around the base of the lip or extension, while they may 1sfrefrom, said lip being essentially parallel with! the bore of thefirearm but offset with relation thereto, the space above the lip beingleft free and unobstructed.

2. An accuracy attachment for firearms comprising a lip or extensiondirectly on the extreme end of the barrel and entirely forward thereofand projecting forward therefrom generally parallel with the bore butoffset with relation thereto and arranged to provide free escape for thegases issuing from the barrel in all'directions opposite the lip.

3. An accuracy attachment for firearms comprising a lip or extensionrigid on the extreme end of the barrel and lying entirely forwardthereof, said li being transversely curved, offset with relatlo'n to thebore of the barrel so that the inner wall of the extension possesses alonger radius with relation to the axis of the barrel than does the wallof the bore of said barrel, and the space above the lip being left freeand unobstructed.

ALVIN M. CRAIG.

Witnesses WARREN B. HUTCHINSON, M. G. ODoNNnLL.

